1. Field of the Invention
The present invention relates to a radio transmission system and an electronic device, and particularly to a mechanism of signal transmission between electronic devices when one electronic device is mounted in the other electronic device (on a main unit side, for example).
2. Description of the Related Art
For example, signal transmission may be made in a state of one electronic device being mounted in another electronic device. For example, a card type information processing device typified by a so-called IC card or memory card including a central processing unit (CPU), a nonvolatile storage device (for example a flash memory) and the like can be mounted (detachable) in an electronic device on a main unit side (see Japanese Patent Laid-Open Nos. 2001-195553 and 2007-299338 (hereinafter referred to as Patent Documents 1 and 2)). The card type information processing device as an example of one (first) electronic device will hereinafter be referred to also as a “card type device.” The other (second) electronic device on the main unit side will hereinafter be also referred to simply as an electronic device.
Mounting the card type device in the electronic device on the main unit side provides advantages of taking out data, increasing storage capacitance, and adding additional functions, for example.
In this case, when an electric connection is established between the electronic device and the card type device, the electric connection is achieved by mounting the card type device in the electronic device via a connector (electric connecting means) in a related-art mechanism. For example, in order to establish an electric interface connection to a memory card, a terminal part is provided to the memory card, and the electronic device is provided with a slot structure (an example of a fitting structure). The memory card is inserted into the slot structure of the electronic device to bring the terminal parts into contact with each other. This is an idea of providing a signal interface by electric wiring. Incidentally, the slot structure also has a function of means for fixing the memory card.
There are generally standards for casing shapes and the signal interface including the terminal part and the slot structure, and an electrical and mechanical interface between the terminal part and the slot structure is defined according to the standards.
For example, Patent Document 1 (paragraph 19, FIG. 2 to 5) shows that a card interface 21f is provided inside a controller LSI 21, and that the card interface 21f is connected to an electronic device via a plurality of signal pins (corresponding to the terminal part).
In addition, Patent Document 2 (paragraph 42, FIG. 1, 3, 5 and the like) shows that an external connecting terminal 24 (corresponding to the terminal part) connected via a conductive via to a wiring pattern for connection to an external device (corresponding to the electronic device) at a determined position of a standardized casing 19 is provided.